Method and means to run carburetor internal combustion engines



Nov. 3, 1936. GUSTAFSSQN 2,059,334

METHODAND MEANS TO RUN CARBURETOR INTERNAL COMBUSTION ENGINES Filed Aug. 3, 1954 3 Sheets-Sheet l ITFIIIIH Nov. 3, 1936. N. G. A. GUSTAFSSON METHOD AND MEANS TO RUN CARBURETOR INTERNAL COMBUSTION ENGINES Filed Aug 3, 1954 3 Sheets-Sheet 2 Z 4, y M /l w; mw 7 5 a t I I \TMJ m J /0 0 0 a M a .b M I. M w N w 5 l L M |l3| I I ,w 7 M m QUwNNk 1 1 mu -W: name-m l Nov. 3, I N. G. A. GUSTAFSSON 2,059,334

METHOD AND MEANS TO RUN CARBURETOR INTERNAL COMBUSTION ENGINES Filed Aug. 3, 1954 5 Sheets-Sheet 3 o m b n v Mm W. Vb

N a A 1 O O O I a J l l m 0 l 5 6 3 \V I m gm, ww w M 0 u M 635 W 1 I, p, y 2 .v \\-w\\\-r mains then constant.

Patented Nov. -3, I936 UNITE METHOD AND MEANS TO RUN CARBURETOR INTERNAL COMBUSTION ENGINES Nils Gustaf Albert Gustafsson, Stockholm,

Sweden, assignor in Svenska Ackumnlator Aktiebolaget Jungner, Stockholm,, Sweden,

a corporation of Sweden Application August 3, 1934, Serial No. 738,358 In Germany August 8, 1933 4 Claims.

Since several years attempts have been made to run carburetor internal combustion engines on heavy fuels. By very strong preheating of the fuel or the air-fuel mixture, e. g. by means of the heat of the exhaust gases of the engine, attempts have been made to transfer the heavy fuel from liquid state into vapor in order to introduce same in the vapor state into the cylinders of the engine. When the engine is running at full or approximately full load the temperature of the exhaust gases maybe sumciently high to cause complete vaporization of the heavy fuel, but already at half load the heat of said gases is insufficient 'for effecting such vaporization and at still lower load and especially on idle running the vaporization becomes very incomplete.

Another drawback in running common carburetor internal combustion engines on heavy fuels resides in the fact that a contamination of the lubricating oil by fuel condensed therein and entering the crank case of the engine cannot be avoided. Such a dilution or contamination of the lubricating oil occurs also when the engine is run on gasoline, but in such cases, as a rule, a certain purification of the oil takes place automatically on account of the working temperature of the oil being relatively high, about 50 to (3., whereas the temperature of vaporization of gasoline is low. When running the engine on gasoline the dilution of the lubricating oil only rises to a given maximal value and re-- On the contrary, when using heavy fuels having, consequently, a higher temperature of vaporization, the dilution of the lubricating oil by fuel condensed therein in- .creases to such an extent that the oil can no longer fulfill its lubricating function.

In order to eliminate these drawbacks it has already been proposed to insert in the circulation system of 'the lubricating oil a means for expelling from said oil the fuel or other contaminating foreign matters contained therein, e. g. by means of the .heat of the exhaust gases. At low load and especially on idle running the temperature of the exhaust gases is, however, insufliciently high to effect a sufficient expulsion of heavy fuel from the oil. In certain cases, e. g. in boat engines, which, as known, are normally running at full load and on manmuvring must be adjusted into idle running position attempts to eliminate this drawback have been made by running the engine on gasoline on idle running but on heavy fuel at conditions of load.

fact that the fuel-air mixture introduced into the cylinders must have a very high temperature the dew-point of such a mixture containing heavy fuel being very high. So for instance, a mixture of kerosene and air has a, dew-point of about C. On account of this high temperature on the one hand the volumetric efliciency of the engine will be very low resulting in low power and high fuel consumption and on the other hand the compression ratio to be used must be very low as the temperature ,at the end of. the compression stroke depends on that at the beginning of said stroke and, consequently, the temperature at, which the fuel-air mixture is introduced into the cylinders determines the useful compression ratio. r

On account of these circumstances the attempts to use cheap and less inflammable heavy fuels, as for instance kerosene, solar-oil etc., for running carburetor internal combustion engines have heretofore failed.

The principal object of my invention is to provide' a "method and means whereby it will be possible ,to run on heavy fuels such carburetor internal cgimbustion engines which are constructed to be run on a light fuel.

'To this end I control the supply to the engine of a light fuel and a heavy fuel in such a. manner that during such periods of time when the temperature of the exhaust gases is insufflciently high to permit expulsion to a sufllcient degree from the lubricating oil of heavy fuel having entered said oil as impurity, exclusively or essentially light fuel is supplied to the engine, whereas during such periods of time when said temperature is sufficiently high for effecting expulsion from the oil of heavy'fuel, fuel is expelled heavy fuel, andiatfull load or approximately full load exclusively or essentially with heavy fuel.

'When the engineis cold, exclusively light fuel is supplied to the engine at no load as well as under load conditions.

Consequently, by supplying exclusively light fuel, e. g., gasoline, on idle running and by successively decreasing the quantity of gasoline and substituting therefor heavy fuel, e. g., kerosene, according as the load increases and the temperature of the exhaust gases rises, the disadvantages above referred to are eliminated. Further it is not necessary to force the preheating of the fuelair mixture to the high degree which has heretofore been required, but the temperature in the intake of the engine may be kept at about 60 0., thus at the same value as in ordinary gasoline engines. Thereby the advantages are attained on the one hand that it is not-necessary to reduce the compression ratio of the engine, when changing from gasoline to kerosene, and on the other hand that in kerosene drive the power of the engine and the fuel'consumption are kept at about the same values as when running the engine on gasoline, depending on said low compression ratio and on the low temperature of the fuel-air mixture introduced. These advantages have hitherto not been obtainable.

The quantity of heat to be supplied to the intake of the engine is preferably supplied from a hot surface or heatedportion of the wall of the intake (so called hot spot arrangement).

Another object of my invention is to provide a fuel system for carburetor internal combustion engines for carrying out the above-said method, said system comprising a carburetor arrangement for light fuel as well as heavy fuel, in combination with a vaporizer or rectifier to be connected to or inserted into the lubricating oil system of the engine for the expulsion of fuel contained in said oil.

The carburetor arrangement may consist of a single carburetor to which the two fuels are supplied in the above-said manner, or of two carburetors, one for light fuel and one for heavy fuel. Preferably, I use a so-called 'bi-fuel carburetor for both kinds of fuel.

The carburetor arrangement or bl-fuel carburetor may be constructed to supply in all positions of the throttle valve of the engine a constant or decreasing quantity of light fuel so that this supply becomes independent of the vacuum in the intake of the engine.

In case of a bi-fuel carburetor this may be constructed according to the principles set forth in my co-pending patent application Serial No. 690,727, filed September 23, 1933. In this application a bi-fuel carburetor is shown having an adjustable change over device adapted to control the supply of the two fuels to a main nozzle and auxiliary nozzles of the carburetor, said change over device being so corgtructed as to allow supply either of light fuel alone or of both fuels simultaneously or of heavy fuel alone.

According to my present invention I may modify the bi-fuel carburetor disclosed in said prior application so as to allow supply of the light fuel to a nozzle of the carburetor in all positions of adjustment of the change over device. By this means the advantage is gained that the fuel-air mixture supplied to the cylinders of the engine will always contain a given quantity of the light fuel which is distributed in said mixture in the form of greater or smaller particles and serves to facilitate the ignition of the heavy fuel. Hereby the combustion of this latter fuel becomes more complete than when using heavy fuel alone, and further the exhaust gases become practically free from smoke, the acceleration of the engine is increased and the dilution of the lubricating oil by heavy fuel is considerably reduced.

In the modification of a bl-fuel carburetor above described in which, consequently. an auxiliary nozzle, e. g., the no load nozzle, is permanently connected with the supply for light fuel,

whereas the main nozzle may by means of the 'change over device be connected either to said supply of light fuel or to that of heavy fuel or be entirely cut 011', the supply of the more expensive light fuel has a tendency to increase according as the suction in the intake of the engine increases resulting in the fuel-air mixture introduced into the cylinders of the engine becoming unnecessarily rich in light fuel causing sinking of the fuel economy.

In order to avoid this drawback I provide means in the connection between the adjustable change over device and an auxiliary nozzle, or within said nozzle, said means being adapted automatically to limit the supply of the light fuel to said nozzle which in all positions of the change over device communicates with the supply of light fuel. Preferably, said means consists of a throttling means of any kind.

The vaporizer or rectifier which according to 4 my invention is to be inserted into or connected with the lubricating oil system of the engine may be of any suitable type.

In order to effect rapid and suflicient expulsion of the fuel from the lubricating oil I may use a rectifier having one or more surfaces heated directly, e. g., by means of the exhaust gases, and so arranged as to cause the contaminated oil to flow downwardly on said surface or surfaces, e. g., by its own weight, in the form of a relatively thin layer or film having a free surface of expulsion.

To facilitate the expulsion of the fuel I may dispose the heating body on which said expulsion surface or surfaces are provided in a chamber and provide means to effect the formation of a more or less high vacuum in said chamber so as to cause the expulsion to take place at a relatively low temperature, said vacuum being, for instance, effected by connecting the expulsion chamber to the intake of the engine. To render possible to transfer the purified oil from the expulsion chamber to the crank case of the engine I may, in this case, combine said chamber with a receptacle for the purified oil adapted periodically to be brought into communication with the atmosphere.

In certain cases and especially when a rather non-volatile fuel is used, I may, instead of providing for the formation of a vacuum inthe expulsion chamber of the rectifier, combine the latter with means to bring a gaseous medium from a source connected to the rectifier to pass through the chamber serving for the expulsion of the fuel vapors, in such a quantity that medium admixed with fuel vapors is removed, when the vapors have reached their saturation pressure or before.

This supply of a gaseous medium to facilitate the expulsion of the fuel vapors preferably takes place continuously, in which case the expulsion chamber is in constant communication with the source of said medium, but the supply may also take place intermittently, for instance by means of a valve adapted periodically to open said communication, the intervals between the consecutive periods of keeping said communication open hav- Preferably, however, air

The gaseous medium or air may be preheated before it enters the rectifier, and said preheating may be efl'ected in any suitable manner, for instance by utilizing the heat of the exhaust gases of the engine or the heat in the rectifier proper when air is being used as gaseous medium.

The means to bring the medium t Pass through the expulsion chamber may be of any suitable kind, depending on'the'prevailing working conditions. The medium may be pressed into the expulsion chamber at a suitable pressure, e. g. by a pump, or said chamber'may be connected to a suitable source for producing suction, for instanceto the intake of the engine, or it may be possible to employ a combination of both.

The heating of the oil-fuel mixture in the expulsion chamber and the preheating of the gaseous medium and/or the entering lubricating oil may be effected in any suitable manner. Generally, however, I utilize the heat in the exhaust gases of the engine for this purpose. I

My invention will be best understood by ref erence to the following description, when taken in connection with the accompanying drawings of specific embodiments thereof while its scope will be more particularly pointed out in the appended claims.

In the drawings:--- P Fig. 1 is a diagrammatic view of a fuel supplying device according to m'yinvention which without any difliculty may be connected or combined with a gasoline engine of common types, e. g. an

automobile motor, in substitution for the normal gasoline carburetor.

Fig. 2 isa diagrammatic view of an embodiment according to my invention of acarburetor to be used in the fuel system according to Fig. 1 and having a change over device to control the fuel supply conduits.

to Fig. 3 is a view of a modification of said change over device in a given position.

Fig. 4 is a diagrammatic partial view of a modification of the carburetor arrangement according to Fig. 2.

Fig. 5 is a longitudinal sectional-view of an embodiment according to my inventioii'of a vaporizer or rectifier to be used in the fuel system according to Fig; 1. v

Fig. 6 is a sectional view along the line t-t in Fig. 5 through a lubricating oil receptacle appurtenant to said rectifier.

Fig. 7 is a view of a cover of said receptacle, seen from below.

Fig. 8 is a detail view of a part of a valve of the rectifier.

Fig. 9 is a longitudinal sectional view of another embodiment of a vaporizer or rectifier according to my invention.

Fig. 10 is a cross-sectional view along the line it-tt in- Fig. 9, a cover for a thermostat cham ber inserted into the exhaust gas inlet being removed.

Fig. 11 is a sectional view along the line i lI-M of Fig. 10, illustrating also the thermostat chamber.

Fig. 12 is a partial view of a modification of Fig. 9.

According 'to Fig. lreference numeral 2t designates a carburetor device, El a preheater connected with said carburetor deviceifi a vaporizer or rectifier, it an oil pump or the engine, it a fuel pump of the engine for heavy fuel, e. g. kero sene, t5 the intake of the engine, ft the exhaust thereof, 2'! a conduit connected with a supply for light fuel, e. g.-gasoline, and adapted to be connect'ed with the carburetor 20, and 28 a. conduit connecting said carburetor device 20 with the fuel pump l4, said conduit 28 being wound spirally around the exhaust 26 as shown at 29.

the rectifier is connected with the oil pump 23,

by a pipe to with the crankcase of the engine and by a pipe 36 with the intake 25 thereof.

The combined carburetorand rectifier operates as follows:

The engine is started on gasoline. As long as the engine is cold, gasoline is exclusively supplied to same from the carburetor at no load as well as at all conditions of load. When the engine has become warm and the temperature of the exhaust gases is sumciently highto render possible by means of the rectifier 22 to expel from the lubricating oil heavy fuel absorbed therein, a change over device appurtenant to the carburetor is adjusted in such a manner thateither both gasoline and kerosene or kerosene alone can be supplied to the engine, said change over device being more fully described later on with reference to FigsuZ and 3. When running the engine wholly or in part on heavy fuel, a contamination of the lubricating oil by fuel, especially heavy fuel, occurs. By the pump 23 the contaminated oil is pumped through the pipe 3 t into the rectiher 22 in which the fuel, is expelled from the mixture of fuel and oil by means of heat delivered by the exhaust gases, said fuel being supplied to the intake 25 of the engine through the pipe t t. As will be more fully described lateron the arrangement is, preferably, such that, when the temperature of the exhaust gases increases, the quantity of gasoline supplied to the engine is successively decreased, whereas the quantity of kerosene is increased to the corresponding degree. Q

By the addition of gasoline at partial loads the combustion in the cylinders of the engine of heavy fuel will be so complete as to cause the engine to run free from smoke and without smell and formation of soot, the heavy fuel being in such cases introduced into the cylinders in the form of drops. on the other hand, at high loads the quantity of heat at disposal during the compression stroke is suficient for the vaporizationof the heavy fuel, and consequently, the addition of light fuel may during such periods be small or wholly dispensed with.

The embodiment of the.carburetor designated by 2t in Fig. l and shown in Fig. 2 is of the socalled bil-fuel carburetor type. In this figure, ll designates the mixing chamber of the carburetor to be connected to the intake 25 (compare Fig. 1) and provided with spraying means for the main fuel in the form of a narrow annular slot M. The fioat chambers of the carburetor are designated by M an M, chamber at containing light fuel, e. g. gaso ne, and chamber tit heavy fuel, e. g. kerosene. The chambers t3 and M are each by a conduit t5 and M, respectively, connected with a common change over device ti, said device controlling the supply of fuel longthe one hand to a main nozzle tit arranged. in -t ing to the spraying slottt other hand to a plurality of auxiliary nozzles, viz. a transition nozzle 50 arranged in a conduit 5|, a no load nozzle 52 arranged in a conduit 53 and a starting nozzle 54 arranged in a conduit 55. The throttle valve of the engine is designated by 56.

Arranged in the connection of the gasoline float chamber 43 with the no load nozzle 52 is a throttling means serving to limit the supply of gasoline to said nozzle. In the embodiment shown this means consists of a throttling member 60 arranged in a supply conduit 6| leading from the change over device to all auxiliary nozzles 50, 52 and 54 in common, the throttling member being, consequently, common to all said nozzles. Arranged in the connection of the gasoline float chamber 43 with the auxiliary nozzle or nozzles before the no load nozzle. 52 and, in the embodiment shown, also before the other auxiliary nozzles 50 and 54, reckoned in the direction of flow of the fuel is a space or chamber 62 communicating with the atmosphere by means of an opening 63. This opening 63 forms a common air.inlet for all auxiliary nozzles and is arranged between said nozzles and the throttling member 50, reckoned in the direction of flow. The conduits 5|, 53 and 55 in which the auxiliary nozzles are arranged open into the chamber 62 and form liquid seals together with said chamber and the liquid contained therein. Evidently, the air inlet 63 should be arranged before said liquid seals.

As seen from the figure the change over device 41 is common to both fuel float chambers 43, 44 and also to all nozzles. The device may be adjusted into three different positions.

In the position I of the change over device 41 gasoline is supplied to all nozzles, the main nozzle 48 as well as the auxiliary nozzles 50, 52 and 54, whereas the supply of kerosene is entirely cut off. In this position the carburetor operates as a common gasoline carburetor. As stated above the change over device occupies this position on idle running and at all load conditions, when the engine is cold, and at no load, when the engine is warm.

In the position II of the change over device 41 gasoline is supplied to all auxiliary nozzles 50, 52 and 54 and kerosene to the main nozzle 48. At no load, that is when the throttle valve 55 is closed, the engine runs on gasoline alone in this position of the change over device 41, on account of the vacuum in the mixing chamber 4| being insufliclently high to cause any heavy fuel to be sucked in through the spraying means 42. The change over device 41 should be adjusted into this position II, when the temperature of the exhaust gases is so high that the rectifier 22 (Fig. l) is capable of expelling from the lubricating oil heavy fuel contained therein. When the throttle valve 56 is opened, the engine changes to run mainly on kerosene, the supply of gasoline being successively reduced according as the load increases and, consequently, the temperature of the exhaust gases rises, this depending, in part upon the fact that the main nozzle 48 opens into the mixing chamber 4| before the throttle valve 56 and the auxiliary nozzles 52 and 54 in or after this valve.

In the position III of the change over device 41 the supply of light fuel or gasoline is according to Fig. 2 entirely out off and, consequently, heavy fuel alone is supplied to the mixing chamber 4| through the main nozzle 48 and spraying means 42. If in this position of the change over device 41 the throttle valve 56 is closed. the engine. will stop on account of lack of fuel. This position of the change over device is utilized especially. in stationary engines and boat engines which operate at continuous or full load.

The carburetor operates as follows:

Before the engine is started, the chamber 62 and the conduits 5|, 53 and 55 stand filled with gasoline to the same level n as in the gasoline float chamber 43. When the engine is started, the quantity of gasoline contained in the chamber 62 is sucked into the mixing chamber 4| through the starting nozzle 54 and the no load nozzle 52 and from said chamber 4| into the engine cylinders. When the level of the gasoline in the chamber 62 reaches the lower orifices of the conduits 53, 55 and, consequently, the liquid seals of said conduits are broken, a mixture of gasoline and air from the air inlet 63 is sucked into the mixing chamber more or less intermittently. When then the throttle valve 56 is opened, the main portion of fuel (gasoline or kerosene according to the position of the change over device 41) is sucked into the mixing chamber 4| through the main nozzle 48 and the spraying means 42 on account of the vacuum in said chamber. However, gasoline continues to flow into the chamber 62. By means of the throttling means 60 this quantity of gasoline is, however, limited to an amount mainly corresponding to the relatively small head between the level n in the gasoline float chamber 43 and the lower orifices of .the pipes 53, 55. With other words, this quantity of gasoline will be constant or nearly constant per unit of time and, consequently, independent of the vacuum in the mixing chamber.

In Fig. 3 a modification of'the change over device is shown according to which said device permits light fuel or gasoline being supplied also in its third position, although this supply is somewhat choked. According to this modification gasoline is, consequently, supplied to the engine in all positions of the change over device which is, per se, advantageous with respect to the combustion of the heavy fuel, the accelerating property of the engine etc. Because, however, as stated above, this quantity of gasoline does not increase according as the vacuum increases in the intake of the engine but is constant or even sinking per unit of time at all conditions of load, the improved economy of service aimed at is still attained.

As shown in the drawings the change over device is so formed as to prevent in all its positions the supply of a mixture of the two kinds of fuel, said fuels being in the position II in Fig. 2 and III in Fig. 3 supplied to the mixing chamber through separate nozzles. As the vapor pressure of gasoline is considerably higher than that of kerosene, the gasoline will be completely vaporized, whereas the kerosene will only be atomized facilitating to a high degree the vaporization of the latter fuel.

The adjustment of the change over device into different positions may be effected manually. In certain cases it may be preferred, however, to effect this adjustment more or less automatically. So for instance the change-over device may be controlled by a thermostat actuated by the temperature of the exhaust gases (or by that of the cooling medium) in such a manner that when the temperature surpasses a predetermined value the change-over device is adjusted from position I to position II. The adjustment of the device from position II into position III may be controlled by a vacuum cylinder, membrane or the like communicating with the intake and eflecting adjustment of the change-over device on lower vacuum into position HI and on higher vacuum into position II. Such a device may be used at advantage for instance in automobile motors.

Although automatic adjusting devices of the type above described are self-explaining for a person skilled in the art, I have in Fig. 2 diagrammatically illustrated embodiments of same.

In connection with the position II of the change-over device 41 I have shown a thermostat consisting of a bi-metallic spiral spring I10 housed in a casing "I connected to the exhaust of the engine, e. g. pipe 26 of Fig. 1. The spring is connected at its one end with the casing and at its other end with a shaft II2,-and secured to said shaft I12 is an arm I13 connected to the valve member of the change-over device 41 by a suitable linkage I14. By suitably selecting the heat expansion coeflicient of the two layers of the spring I18, it is evident that ,a decrease in temperature of the exhaust gases will result in an adjustment of the change-over device from position 11 to position I.

In connection with position III of Fig. 2 I have shown a cylinder I15 having a piston I15 actuated by a spring I", the space below the piston communicating with the intake of the engine, e. g. pipe 25 in Fig. 1. By means of a suitable linkage I18 the piston is connected to the valve member of the change-over device. The operation is selfexplaining. In most cases, the control devices shown in connection with positions .II and III are used separately, but it is also possible to use these devices in combination, in which case the position of the change-over device 41 will be determined by the sum of the eifects of the thermolimit the supply of the light fuel, e. g. gasoline.

to the no load nozzle 52 is provided within said nozzle, the nozzle being adjustable in accordance with the suction in the intake of the engine. By means of conduits 53 and 415, the no load nozzle is directly connected with the light fuel chamber 43 and is formed with a conical valve seat I80 co-operating with a corresponding conical valve body I 8I.- The valve body II is secured at the lower end of a spindle I82 which at its upper end is secured to a membrane I83, bellows or the like, arranged in a chamber I84 which is'connected with the intake. of the engine in such a manner that the membrane I83 is actuated on its one side by the pressure in saidintake and on with a carburetor according to my invention.

With reference to these figures reference number 18' designates a heating body which has the form of a conical screw having a plurality of threads.

The lubricating oil contaminated and diluted by fuel, especially heavy fuel or kerosene flows downwards on the thread surfaces 1'2 for the purpose of rectification, said surfaces increasing in size from the top and downwardly on account of the conical shape of the screw. The heating body III is screwed onto a cover I8 of a lower receptacle 14 for purified lubricating oil and is provided with a central channel I5 communicating with a channel I6 in the cover 13, said last-mentioned channel being adapted to be connected with the exhaust of the engine, (e. g. 26, Fig. 1) by means of a nipple 11 (see Fig. 6) screwed into the cover 13 so as to cause the exhaust gases to pass through pipe 32, Fig. Land the channel I5 of the heating body thereby heating same. In order to control the supply of exhaust gases a valve member I8 is provided in the channel I8 in the cover 18, said member 18 being adjustable to and from the inner end of the nipple I1 and having a spindle I9. screwed into a sleeve nut 80 connected with the cover, a locking nut 8| serving to secure the 81 to the casing 82 and, simultaneously to the heating body III a nipple 88 is screwed into the upper end of the heating body and into thelid 81, the upper threaded end of said nipple extending beyond the lid. Engaging said upper end isa pipe bend 89 forming outlet for the heating gases having passed through the control channel 15 of the heating body and through the nipple 88, said pipe bend 89 being adapted to be connected to an exhaust for said gases, e. g. pipe 33 in Fig. 1.

Provided at the upper end of the heating body III is a dished plate 90 having apertures ill and adapted to collect lubricating oil entering the rectifier through a nipple aland'ga channel in the lid 81 and to guide this oiltojthe thread'isurfaces 12 of the heating body. 'l. hell.lliiiple 92 is adapted to be connected with the crankcase of the engine, e. g. through pipe 34 in Fig. 1, from which the oil is supplied in known manner by meansof a pump, e. g. 28 in Fig. 1. Further,- the lid 81- carries another nipple 84 communicating bya channel 85 in the lid with the space 83 between the casing 82 and the heating body I0 and adapted to ..be connected (e. g. through pipe 86 in Fig. 1) with the intake of the engine, e. g. pipe 25 in Fig. 1.

Channels 98 in the cover I8 connect the space 83 with the interior of the receptacle I4. Providedin this receptacle is afloat 91 movably carried by an arm 98 adapted to engage a blade spring 99 secured at its one end as at I 00 to the inside of the cover 13 and adapted to actuate a valve device for admitting air into the receptacle 14 in the manner to be described. This valve device comprises a valve seat IUI fitting tightly thereon. In order to lock the lidj having the form of a screw plug threaded into the cover I3 from the inner side thereof, the upper end oi. said plug being conically chamfered and provided with a central recess I82 so as to form an upper relatively sharp edge I03 at the top of the plug. Loosely resting on this edge I08; is a plane valve plate I84 provided on its underside with a shallow groove I05 (see Fig. 8) and 1 adapted to be actuated by a pin I88 extending through the plug Illl and bearing on the free end of the blade spring 99. Channels II in the plug IOI connect the recess or valve chamber I02 with the interior of the receptacle I4. On its underside the plug IOI is provided with a recess I08 (see Fig. 7) to permit upward movement of the blade spring 99. Threaded onto the upper end of the plug IOI is a sleeve nut I09 having lateral apertures I I0 and forming a casing for the valve.

Provided at the bottom of the receptacle I4 is a drain valve comprising a sleeve III threaded into the bottom I I2 from the inside thereof and conically chamfered at its outer end so as to form a relatively sharp edge H3 of the same shape as that on the valve plug IOI, said edge H3 serving as valve seat for a valve body I I4 having the form of a dished plate with a plane bottom. In its open position this plate II4 bears on the upper edge of a sleeve I I5 provided with lateral apertures H6 and secured to a sleeve nut I I1 screwed onto a threaded sleeve-shaped member H8 extending from the bottom H2 and forming together with the nut III a valve chamber II 9 communicating with the surrounding atmosphere by an opening I20. The nut I I! is provided with a downwardly projecting hollow pin I 2I having external threads and carrying a sleeve nut I22 adapted to be connected with an outlet conduit for the purified lubricating oil, e. g. pipe 35 in Fig. 1.

The vaporizer or rectifier above described operates in the following manner.

The lubricating oil collected in the crank case of the engine and contaminated or diluted by fuel, especially heavy fuel, as for instance kerosene, is pumped to' the rectifier e. g. by pump 23, Fig. 1, through pipe 34, Fig. 1, and nipple 92 and flows through the channel 93 into the dished plate 90 whence the oil is distributed through the holes 9| onto the spirally wound surfaces 72 of the heating body I0. This body 10 is heated to suitable temperature by means of exhaust gases entering the rectifier through pipe 32, Fig. 1, and nipple I1 and passing upwards through the central channel I5. The oil mixture flows downwards on the surfaces I2 in relatively thin films, and on accountof the heating the fuel constituents of the mixture are vaporized and returned to the intake of the engine through channel 95, nipple 94 and pipe 36, Fig. 1. On account of the connection of the expulsion chamber 83 with the intake of the engine a partial vacuum is produced in said chamber causing an effective vaporization of the fuel. By the connection of the chamber 83 with the receptacle I4 a partial vacuum will be produced also in this receptacle causing the valves I04 and H4 to be kept closed. The lubricating oil flowing downwardly on the expulsion surfaces I2 and being freed from at least the greatest part of the fuel flows down through the channels 96 of the cover I3 into the receptacle I4. When in said receptacle the oil has risen to a given level the float 91 is lifted causing the float arm 98 to engage the valve spring 99 which is initially stretched on account of the valve plate I04 being kept pressed against its seat with a certain power by the outer pressure. At a given stretching the spring 99 is capable of tilting the valve plate I04 upwardly by means of the eccentrically disposed pin I06 resulting in air flowing into the receptacle 14 through the holes H0 in the nut I09 and the channels I0! of the plug IOI causing apressure equalization to take place between the interior of the receptacle I4 and the outer air. On account thereof the bottom valve H4 is opened and the purified lubricating oil is returned to the circulation system, e. g. to the crank case through pipe 35 in Fig. 1. The float 9I sinks and the air valve I04 is closed causing a partial vacuum to be produced in the space 83 and the receptacle I4 resulting in the bottom'valve H4 being closed. The operation described is then repeated.

On account of the bottom valve H4 being shaped as a cup a liquid seal will be produced around its seat at the lower edge of the sleeve H3. On account of the air valve I04 being provided with a groove I05 (see Fig. 7) through which always a given quantity of air enters the receptacle I4 the vacuum in the latter can be kept at .such a value that the air valve I04 can be opened without too great a power being required for this purpose.

In Figs. 9 to 12 another embodiment of a rectifier is shown adapted to be used according to my invention in combination with a carburetor arrangement for carrying out my improved method.

Referring to this embodiment the rectifier-comprises an expulsion chamber I30 which is limited by a double-walled jacket I3I, an upper cover I32 and a lower dished receptacle I33 serving to collect the purified oil and provided with an outlet I34 for the return of said oil to the crank case of the engine, e. g. through pipe 35 in Fig. 1. Arranged centrally within the chamber I30 is a tube I35 having flanges or other surface-enlarging means provided on the outside thereof, preferably in the form of a helically extending band I36 welded or secured in some other manner to the tube I35, said band I36 forming an extended path of flow for the oil-fuel mixture. At its lower end the tube is screwed into an opening in a pipe I39 extending through the dished receptacle I33, said pipe being closed at its one end as shown at I44 in Fig. 10 and at its other end provided with a nipple I3I (see also Fig. 10) adapted to be connected to the exhaust of the engine or to some other conduit branched off therefrom, e. g. pipe 32 in Fig. 1 so that the exhaust gases are caused to flow upwardly through the central tube I35 whence they escape through an upper pipe bend I38, e. g. through pipe 33 in Fig. 1.

The rectifier is provided with means for heating the entering oil-fuel mixture, before this mixture is brought into contact with the flange I36 serving as an expulsion surface. In the embodiment shown this preheating means consists of a helically shaped pipe I40 arranged around the heating body formed by the flanged tube I35, I 36 and outside the flange I 36, said pipe being adapted to be connected to the crank case of the engine by means of a passage HI and a nipple I42, the mixture of fuel and oil being conveyed to the preheater from the crank case in known manner by means of a pump, e. g. pump 23 and pipe 34 in Fig. 1. The upper part of the helix opens at I43 more or less adjacent to the central tube I35, immediately above the uppermost turn of the band I36, so that the oil-fuel mixture from the tube may flow down upon the helix.

In the embodiment referred to the expulsion chamber I30 communicates at its lower end through a passage I45 with a pipe I46 which extends upwardly along the casing I3I and opens freely into the atmosphere at its upper end. At its upper end the expulsion chamber I30 is provided with a nipple I41 or the like, by means of which said chamber may be connected with the intake of the engine, e. g. through pipe 36 with pipe 25 in Fig. 1 so as to cause air from the pipe I46 to pass through the expulsion chamber I 30.

Arranged in the circular passage I50 of the pipe I39 connecting the tube I35 with the nipple I31 (see Figs. 10 and 11) is adamper l5| secured on a shaft I52 projecting with its upper end into a chamber I53 which is separated from" the passage I50 by a partition i254 provided with openings I55, the chamber I53 being covered at the top by means of a cover 1156 removably secured by screws or the like (see Fig. 11). The openings l55 in the partition lt l are so arranged that the chamber l53 communicates with the passage I50 between the damper l5! and the intake to the rectifier, that is to say behind the damper, counted in the direction of flow of the exhaust gases.

Thechamber I53 serves as a housing for a. thermostat, which according to the invention is of the bi-metal type and consists of a bi-metallic spring 053 attached with its one end to the shaft W2 and adapted to be secured with its other end in one of a number of slots Q59 provided in the wall of the chamber. By inserting the lei-metallic spiral I58 controlling the position of the damper lti in known manner, into, varying slots are, the tension of the spiral and thus also the temperature interval for which the thermostat is to func tion may obviously be varied. On account of the position of the openings 855 the thermostat Hit will adjust the damper it! in accordance with the temperature of the exhaust gases behind the damper.

The apparatus operates in the following manner:

The oil contaminated with gasoline, water and/or kerosene or other fuels and collecting in the crank case of the engine, enters through pipe it, Fig.1, nipple Hi2 and passage Ml into the preheating helix ltd whence it flows down upon the uppermost turn of the helically shaped flange lit of the heating body. By the hot exhaust gases passing through the central tube m5 the heating body l35, lit and thus the expulsion chamber iii] are kept at a suitable increased temperature, so that the oil mixture will be preheated during its passage through the pipe Mid. From the latter the oil mixture flows in the form of a comparatively thin film or layer with a free expulsion surface down the helically shaped; band I135. By the direct supply of heat to the heating body H35, use from the exhaust gases passingthrough the tube, constituents of the oil mixture that are volatile relatively to the lubrieating oil, that is to say fuel diluting the oil mixture, are vaporixed. By the connection of the expulsion chamber ltll to the intake of the engine through the nipple it'll air will be continually sucked in through the pipe Hit and will pass through the expulsion chamber. On account of this continuous passage of gaseous medium, viz. air, through the rectifier, said medium is capable of absorbing a great quantity of fuel vapors, as medium loaded by such vapors is continuously removed when the vapors have reached their saturation pressure, or even before. The expulsion of the fuel vapors will thereby be greatly facilitated. Expelled fuel together with air escape through the nipple ldl to the intake of the motor and thence to the cylinders, where this fuel-air mixture is utilized to perform useful work. The'purified oil flows from the lower end of the expulsion surface 036 down into the collecting receptacle i533 and from the latter through the outlet. pipe lit back to the crank case or some other suitable place.

Fig. 12 shows a modification of the rectifier according to Figs. 9 to 11, in which the enteringair is preheated before it is brought into contact with the expulsion surface or with the oil-fuel mixture flowing down the same. Here, the pipe M5 is disposed in the space of the double-walled jacket i3! and connected with the atmosphere by means of an opening it! provided in the outer wall of the jacket. The pipe M6 may obviously also be arranged within the expulsion chamber or at any other suitable place permitting preheating of the air.

Probably my present invention has its most important application to engines adapted to run on gasoline and mainly operating at partial loads, for instance automobile engines, which according to my improved method and means can be run on heavy fuel without any inconvenience.

When in the foregoing description gasoline and kerosene are especially mentioned as examples made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not at all limitative of the scope of my invention.

It is also to be understood that the language employed in the appended claims is intended to cover all the generic as well as the specific features of the invention herein described What I claim is:-

1. A method of running carburetor internal combustion engines on heavy fuel, which engines are constructed normally to run on light fuel,

comprising controlling the supply of the two fuels in such a manner that during such periods of time when the temperature of the exhaust gases is insufnciently high to allow expulsion from the lubricating oil of fuel which entered said oil as impurity, essentially light fuel is supplied to the engine, whereas during such periods of time, when the temperature of the exhaust gases is sumciently high to effect expulsion from the lubricating oil of heavy fuel, fuel is expelled from said oil and essentially heavy fuel is supplied to the engine.

2. In an internal combustion engine havinga system for the circulation of the lubricating oil,

'the combination of a carburetor arrangement for light fuel as well as for heavy fuel with arectifier inserted into said circulation system for the expulsion of fuel from the lubricating oil, means to heat said rectifier by the exhaust gases of the engine, and means to supply light and heavy fuel to said carburetor arrangement, said supplying means being such that at high temperatures of the exhaust gases allowing expulsion of fuel from the lubricating oil by means of the rectifier, essentially heavy fuel is supplied to the engine, whereas at lower temperatures essentially light fuel is supplied to the engine.

3. In an internal combustion engine having a system for the circulation of the lubricating oil, the tcombination with a carburetor arrangement for'light fuel as well as for heavy fuel, of a rectifier inserted into said circulation system for the expulsion of fuel from thelubricating oil,

means to heat said rectifier by the exhaust gases of the engine, and means tosupply light and heavy fuel to said carburetor arrangement, said supplying means being such that at high temperature of the exhaust gases allowing expulsion of fuel from the lubricating oil essentially heavy fuel is supplied to the engine, whereas at lower temperatures essentially light fuel is supplied to the engine and the quantity of light fuel supplied decreases according as the temperature of the exhaust gases increases.

4. A method of running carburetor internal combustion engines on heavy fuel, which engines are constructed to run on light fuel, comprising supplying essentially light fuel to the engine during periods when the temperature of the exhaust gases is below the point required for expulsion from the lubricating oil of fuel which entered said oil as impurity, and supplying the engine when the temperature of the exhaust gases is above the said point with fuel expelled from the lubricating oil and with essentially heavy fuel having substantially the temperature at which light fuel is supplied to the engine.

N'IIS GUSTAF ALBERT GUSTAFSSON. 

